Motion picture camera drive



Feb. 8, 1938. J. A. BALL MOTION PICTURE CAMERA DRIVE Original Filed Aug. 20, 1931 3 Sheets-Sheet l 1 No m mw $NQWN \h MW, F ll mm L \m Feb. 8, 1938. J BALL 2,107,623

MOTION PICTURE CAMERA DRIVE Original Filed Aug. 20, 1931 3 s t sh t 2 i l g :3 I v v jwewzzov J55ep7z Bal 5% I 1% (y W5.

gi in mun 6 Feb. 8, 1938.

J. A. BAl L MOTION PICTURE CAMERA DRIVE Original Filed Aug. 20, 193] a sheets-sheet s Patented Feb. 8, 1938 MOTION PICTURE CAMERA DRIVE Joseph A. Ball, Los Angeles, Calif., assignor to Technicolor Motion Picture Corporation, Hollywood, Calif., a corporation of Maine Original application August 20, 1931, Serial No. 558,193. Divided and application April 21, 1933, Serial No. 667,222. Divided and this application January 22, 1936, Serial No. 60,233

5 Claims. (Cl. 88-164) The present invention relates to cameras for simultaneous exposure of a plurality of films, especially for the purpose of photography in natural colors, and more particularly to film' confining and advancing devices peculiarly adapted for cameras of this type, this being a division of the copending application Serial No. 667,222, filed April 21, 1933 now Patent No. 2,059,199.

Objects of the invention are to provide a motion picture camera which handles conveniently and exactly a plurality of films, some or all of which may be superposed at the film aperture or apertures of the camera; to provide an arr'angement for feeding a plurality of films from supply reels through a camera of this nature and for again winding them on conveniently arranged take-up reels; to provide an arrangement for such a. camera which permits easy threading of a plurality of films and assures steady progress of the films through the camera along short and uncomplicated paths. Further objects are to .provide a smooth and equalized drive for the film movements which also permits adjustment of the movements without affecting the drive, an improved gear arrangement for driving the various moving parts of the camera, and generally-to provide a camera for taking motion pictures in natural colors which can be easily and conveniently operated and which per mits efiicient commercial production of motion picture films under. conditions similar to those required for the taking of ordinary motion picture negatives. Additional objects of my invention will be apparent from the following description of a typical concrete embodiment illustrated by drawings, in which:

Fig. 1 is a top plan of a motion picture camera incorporating the present invention, with the cover removed and parts broken away;

Fig. 2 is a longitudinal cross-section on line 2--2 of Fig. l with thesupporting block partly broken away;

Fig. 3 is a section on line 3'3 of Fig. 2;

ing removed and with parts shown in section;

Figs. 5, 6 and '7, respectively, are diagrammatic showings of the manner of threading the films; Fig. 8 is a diagrammatic plan 01' the prism system; and v Fig. 9 is a vertical longitudinal section showing the sprocket drive; and 2 Fig. 10 is a side elevation of the central supportingblock with film movement, as seen from .the top of Fig. 1.

Fig. 4 is a detail of Fig. 1, with the gear hous- I The herein disclosed embodiment of the present invention is incorporated in a camera the design of which is completelydescribed in copending application Serial No. 559,193, filed August 20, 1931, of which the above-mentioned copending application Serial No. 667,222 is a division now Patent No. 2,072,091. This camera is adapted for taking photographs in natural colors according to the methods disclosed and claimed in my Patents No. 1,889,030, of November 29, 1932, and No. 2,000,058 of May '7, 1935. This camera comprises a lens system L (Fig. 8) and a prism P with a partially reflecting mirror M and two apertures in planes perpendicular to each other for exposing film G and superposed films B and R, respectively. The various mechanisms ofthe camera are mounted within a sturdy housing in such a manner that the parts which require accurate positioning with respect to each other are combined in separate units which are structurally capable of maintaining the accuracy of position independently of other units and which are separately accessible and adjustable, whereas parts which do not require particular accuracy of assembly and operation are distributed in other units.

Referring especially to Figs. 1, 2 and 3, the housing I, which is made, of ribbed metal parts (preferably of light weight alloy), is built upon a base 2 comprising a plate 3 and a gear box 6. The gear box 6 has receptacles l for the connecting plug of a flexible shaft or other source of power for driving the various movements of the camera. The base plate and gear box are screwed together, threaded bosses 25 being provided for this purpose within the gear box casting. Inside-the gear box is mounted a power distributing device with various gears and a flywheel which will later be described in detail; and on topof the gear box is mounted the central supporting block 5| for the light splitting system and the film movements, and the sprocket drive shaft housing I33 (Fig. 2), both also to be described later. Mounted upon the gear box 6 is a rear wall l6 which also covers a part of each of the longer sides of the camera as shown in Fig. l. The rear wall 16 has a cylindrical bulge H for the sprocket roller mechanism, brackets l8 and I46 (Fig. 2) and a hollow extension I45 (Fig. l) for supporting the sprocket roller mechanism. The front wall 2! forms a housing 22 for the shutter shaft and another housing 23 (Fig. 2) for the shutter drive-shaft.

The block 5| (Figs. 1 and 2), which supports the light-dividing prism system and the two film movements of the camera, is screwed directly to gear box 8. The block has a main crosssection in the shape of an L, and the housing I34 for the drive shaft 2I8 is provided in the angle of this L-shaped support (Figs. 1, 2 and 4). The block 5| has also a prism bracket 55 (Fig. l). The mutually perpendicular machined faces of flanges 53 and 54 and of bracket 55 correspond to the faces of the prism unit. The flanges 53 and 54 have vertical key ways 56 and 51 in their faces for positioning and adjusting the fllm movements, and also openings 58 and 58 (Fig. 4) for the bearings 248 and 248 of the film movement drive shafts hereinafter described. The fllm movements driven through gear wheels 212 and 218 (Fig. 4) are of any conventional design, for example of the type shown in Fig. 18. In that figure, 88 are registering pins mounted on a yoke 61 and a rod 88 with fork 88. The registering pins are reciprocated perpendicularly to the aperture plane by means of cam H which is eccentrically mounted on gear 12. The movement further comprises feeding pins 13 driven by cam 14 of gear 15 which meshes with gear 12. Each movement has an aperture plate 8i and 82 (Fig. 4) respectively, and corresponding back plates 64 (Fig. between which the films are guided. The back plates are integral with aperture flanges 8i and 82 (Figs. 4 and 10) with which they form angular pieces, the flanges being slidably fastened to the block flanges 53 and 54. It will be evident that the aperture plates 8| and 82 form angles of 90 with each other and the bracket face, and that the optical axes of the I light dividing prism P, mounted on bracket 8|,

hubs." Each of the will be substantially perpendicular to the respective aperture plates.

Referring especially to Figs. 1 to 7, bracket I8 on rear wall I8 of the camera. housing, supports a sprocket gear housing I3I. This housing encloses the spiral gear I32 which is mounted on shaft 2I8 ascending from the power distribution gear and protected at its lower part by shaft housing I33 (Fig. 2) screwed to gear box 6. Housing I3I also supports sprocket shaft I35 (Fig. 2) by means of suitable bearings. Within the housing I 3I a gear wheel 138 which meshes with spiral gear I32, is fixed to shaft I35. Keyed to shaft I35 are three sprockets I4I, I42 and I43. Housing I3I and the rear wallv I8 support, with bracket I48, a tube I41 upon which a number of scissor units, corresponding to the number of fllm sprockets used, are rotatably mounted, units I5I, I52, I53, Ill, and I" being shown in Fig. 1. Each scissor unit has a hub ill, a roller arm I ll, a segment arm I88 and a segment I88 (Fig. 9). Two adjacent units cooperate like the blades of a scissors, swinging with their hubs on tube I41, the hubs of two cooperating scissor units being at opp site sides of the arms, with the roller arms intermediate thereof, and the segment arms attached at about the middle of the upper roller arms belonging to sprockets Ill and I42, supports (Figs. 5 and 6), by means of 'pins, four rollers I1I, I12, I13, I14 and 21I, 212, 213, 214, respectively, rollers I12, I13 and 212, 213 respectively. having the purpose of holding the film against the sprockets, whereas rollers HI, 2" and I14, 214, respectively, support the fllms as they leave the sprockets. The lower roller arms, belonging to sprockets Ill and I42, have only three rollers I18, I11, I18 and 218, 211, 218, respectively, arranged like upper rollers I12, I13, I14, 212, 213 and 214. The u errollerarmbelonginstosprocht luhll' only three rollers I8I, I82 and I83 corresponding to rollers I1I, I12 and I13 of the corresponding arm of sprocket I42. The lower roller arm of sprocket I43 has two rollers I88 and I81 arranged similar to rollers I18 and I11 (Figs. 5, 6 and '1).

The segments I88 (Fig. 9) flt with their circular fronts into the bulge I1 of rear wall I8 of the camera, and each segment has two perforations I 88, I88 which are adapted to receive pins I88 of six control knobs I8I, I82, I83, I84, I85 and I88, one for each segment. Holes I88 correspond to the open or fllm releasing position of the roller arms, and perforations I88 to the closed or film engaging position thereof. By pulling back a control knob, the corresponding pin releases the perforations which it engaged, the segment and the roller arm can be rotated and the latter again arrested in its second position by releasing the control knob. The operation of the sprocket device, in cooperation with the fllms and the apertures, will be described hereinafter.

The camera comprises three diiferent power driven units, namely, the aperture unit with two film feeding movements, the fllm sprocket and take-up spool 'drive, and the shutter drive. In order to make the various drives properly accessible and easily and independently adjustable, a power distribution gear is arranged in gear box 8, and the three units are independently driven by three shafts vertically ascending therefrom. The distribution gear comprises bearings 288, 28I, 282, 283, 284, 285 and 288 (Fig. 3) attached to the top of the gear box and three shafts 281, 288, 288. Shafts 288 and 288 are connected with shaft 281 by spiral gears 2H and 2I2. Each of these three shafts 281, 288 and 288 has a square end for coupling it with a flexible shaft or other driving device by means of receptacles 1 (as described before), which permits power supply from either side and from the back of the camera. Vertical shafts 2I8, 2H and 2I8 are driven from shafts 281 and 288 by means of spiral gears 22I, 222 and 223. The shafts U8, 2 and 2I8, respectively, are supported by thrust bearings 228, 221, 228, 23I, 232, 283 (Fig. 2) and run in oil-tight housings 23, I33 and I34, as described hereinbefore. The shutter drive shaft 2I8 drives a shutter shaft 231 over spiral gear 238, supported in housing 22 of front wall 2| by two tapered roller bearings 238 and 238, and accessible through cover screw 248 (Fig. 2). A shutter 45 of conventional design is mounted on an extension of shaft 231 which protrudes beyond the housing 22. The shutter rotates between lens system L and prism system P (Fig. 1), partly in the housing formed by the halves 28 and 38 of front wall and side door, respectively, as described in the above-mentioned application Serial No. 558,193.

In order to assure hamonious operation of the two fllm movements they are both driven from shaft 1 over a single spiral gear wheel 2 gneshing with two gear wheels 2lI and 242 (Fig. 4). Shaft 2I1 runs in housing I34 of the main supporting block 8| in thrust bearings 221 and 232. Gear wheels 2 and 242 drive the two short fllm movement shafts 245 and 241 (Fig. 4) which are supported in aperture flanges 8| and 82 by means of bearings 248 and 248. As described in the above application, the aperture flanges II and 82, mounted on block flanges l3 and 54, are adjustable longitudinally of the block flanges. They may also be adjusted perpendicularly to the block flanges, as for example by shimming. This adjustment is made possible by the peculiar arrangement of gears 2H), 24I and 242 whose mesh is not aifected by such adjustments. Although the timing of the movements is very slightly affected thereby, the adjustment amounts ordinarily to only a few thousandths of an inch and its effect on timing is therefore negligible. These gears are enclosed in a cover 25] in the angle between the two main block flanges (Fig. l). The film movement gear wheels 210 and 212 are fixed to the other ends of shafts 241 and 246, respectively, and drive the registering and advancing pins of the film movements, as described hereinbefore. movements are intermittent in their action they require an intermittent flow of power supply which must be equalized by rotating masses. In order to prevent undesirable interferences between separate flywheels for each movement, a single flywheel 250 is employed according to the present invention. Since it is mounted on shaft 2 I1, either within the gear box as shown in Fig. 2, or elsewhere, it acts upon both movements driven from the same shaft.

The sprocket drive shaft 2I8 supported by thrust bearings 228 and 233 runs within housings I33 and I3I and drives the gear wheel I38 (Fig. l) on shaft I35 by means of spiral gear I32. From pulley I39, also fastened to the sprocket shaft I35, a belt drive 252 leads through housing 43 (Fig. 2) to pulley 253 of the take-up spool gear which again drives in appropriate manner the three take-up spools for the three films which are mounted on a shaft (or on concentrical or parallel shafts) parallel to the sprocket shaft I35.

In order to thread the films, three film spools are inserted in magazine 60 on a shaft (not shown) which is substantially parallel to sprocket shaft I35, the ends of the films being secured to three take-up 'spools similarly arranged on shaft I58. The films are threaded between rollers 25I, 252 and 253 of the light seal 49 so that the three film loops are now arranged parallel side by side. Assuming that the films are to be exposed as described before with reference to Fig. 8, the film B bearing the blue recording emulsion is next to side door 36 and above sprocket roll I4I, the film R with the red recording emulsion is in the center above sprocket roll I42 and the green recording film G is next to the sprocket drive above sprocket roll I43. The films are wound upon their spools in such a manner that the emulsions of films B and G face roller 25I, whereas the emulsion of film R faces roller 252. The scissor units areopened and'kept in this position by knobs I9I to I96, which, during the threading operation, are consecutively moved into closed position where they are again arrested by the knob pins and segments. The films are threaded in the following manner. Each film is first inserted between rollers HI and I12, 21I and 212, respectively, and I8l and I82, respectively (Figs. 5, 6, '1), and films B and R, after the sprocket pins are inserted into the film perforations, are brought out again between rollers I13 and I14 and 213 and 214, respectively (Figs. and 6). Film G emerges between sprocket roll I43 and. roller I83 (Fig '7). Films B and R are now turned a quarter turn longitudinally, and a half turn laterally towards aperture plate SI (Fig. 1). whereby the two films are superposed so that they form a single loop, and they are now threaded into the film gate, the two emulsions being in contact with the blue sensitive film nearest to prism Since the P, as shown in Fig. 8. Upon emerging from the film gate, the two superposed films B and R are again separated and returned to their sprocket wheels with loops converse of those between the upper rolls and the film gate. The films B and R are now introduced between rollers I11 and I18 and 211 and 218, respectively, their perforations engaged at the lower side of the sprocket rollers HI and I42, where they are secured by rollers I16 and I11 and 218 and 211, respectively, and brought out overthe upper side of rollers HI and 21I, respectively. As described before the emerging films are threaded between rollers 252 and 253 of the light seal and are ready to be wound upon the three take-up spools in magazine 50, which are arranged similar to the spools in magazine 68 and driven from pulley 253.

It should be understood that the present disclosure is for the purpose of illustration only, and. that this invention includes all modifications and equivalents which fall within the scope of the appended claims.

I claim:

1. A motion picture camera comprising a rigid supporting block, a driving gear wheel on said 25 block, two film gates, two film movements for transporting film through said gates each having a driven gear wheel, and means for mounting said gates and said movements on said block with said gear wheels meshing, said driving and driven gear wheels being maintained in definite relative position by said block.

2. A motion picture camera comprising a rigid supporting block, a driving spiral gear wheel on said block, two film gates, two film movements for transporting film through said gates each having a driven spiral gear wheel, and means for mounting said gates and said movements on said block with said gear wheels meshing, said driving and driven gear wheels being maintained in definite relative position by said block.

3. A motion picture camera comprising a base plate, driving means on said plate, a rigid central supporting block fixed to said plate, a driving gear wheel mounted on said block and rotated by said driving means, two film gates, two film movements for transporting film through said gates each actuated by a driven gear wheel, and means for mounting said gates and said movements on said block with said driving and .driven gear wheels meshing, said gear wheels being by said block maintained in rigid position relatively to each other and to said plate.

4. A motion picture camera comprising a base plate, a driving main shaft extending along said plate, a rigid central supporting block fixed to said plate, two film gates, two-film movements for transporting filfn through said gates each actuated by a driven film movement gear wheel, means for mounting said gates and said movements on said block, a group of substantially coaxial film sprockets for feeding film to said movements actuated by a driven pinion, a film movement shaft rising from said plate, driven from said main shaft, having a driving gear wheel mounted on said block and meshing with said film movement gear wheels, and a sprocket shaft rising from and mounted on said plate, driven from said main shaft and having a driv- 1 ing gear wheel meshing with said pinion, said plate, a main drive shaft in said box mounted for transporting film to said movements mounted underneath said plate, a central supporting block on said plate and actuated by a driven pinion, a fixed to the upper side or said plate, two fiim second auxiliary shaft extending through said movements each actuated by adriven gear wheel, plate driven from said main shaft and having a means for rigidly mounting said film movements driving gear wheel meshing with said pinion, on said block, an auxiliary shaft extending and a flywheel fixed to one oisaid auxiliary through said plate driven from said main shaft shafts within said box.

and having a driving gear wheel meshing with JOSEPH A. BALL said driven gear wheels, a group of sprockets 

